ช่วยดูการใช้ query แบบใช้ select ซ้อน select (ms sql server2008 r2)

SELECT 
	groupno, indicatorno, indicator, unit, bmntarget, 
	(SELECT 
		CASE 
			WHEN IndicatorReport.indicatorno = 1 THEN SUM(q01a) 
			WHEN IndicatorReport.indicatorno = 2 THEN SUM(q02a) 
			WHEN IndicatorReport.indicatorno = 3 THEN SUM(q03a) 
			WHEN IndicatorReport.indicatorno = 4 THEN SUM(q03a) 
			WHEN IndicatorReport.indicatorno = 5 THEN SUM(q05a)
		END 
			FROM ( 
				SELECT * 
				FROM TambonBMN2 LEFT JOIN TambonBMN3 ON TambonBMN3.year = TambonBMN2.year AND 
				TambonBMN3.villid = TambonBMN2.villid WHERE TambonBMN2.year = 2545 AND 
				TambonBMN2.villid LIKE 'NULL%' ) res_all
	) as result_all
FROM 
	IndicatorReport 
ORDER BY groupno,indicatorno